As is well known in the art, recently, it becomes possible to record video data in a compressed form as well as audio data on an optical disk having the same diameter of 12 cm as an audio CD (Compact Disk), for example. As this type of optical disk, for example, a CD-ROM (Read Only Memory) is popularly used in a wide range of field from the education field to information field.
Further, recently, a DVD-ROM or the like which is an optical disk having the same diameter as the CD and on which main video data of an amount corresponding to an approximately 2-hour movie, 8 types of audio data items and sub-video data representing 32 types of captions are recorded is developed. At present, a DVD standard using the MPEG (Moving Picture Image Coding Experts Group) 2 compression system based on the international standard for video data and using the AC-3 compression system for audio data is proposed.
According to the DVD standard, MPEG2 is used for the video compression system according to the MPEG2 system layer, the AC-3 system and MPEG system are supported as the audio compression system, and sub-video data obtained by subjecting bit map data to the run-length compression as the caption and control data (navigation pack) for special playback such as playback at the time of quick feeding and quick returning are additionally provided.
Further, in the DVD standard, ISO (International Organization for Standardization) 9660 and micro UDF (Universal Disk Format) are supported so that data can be read by use of a personal computer and the like, for example.
At present, not only the playback only optical disk such as the DVD-ROM described above but also an optical disk such as a DVD-RAM (Random Access Memory), for example, in which data can be programmed or rewritten is developed and an apparatus for recording/playing back data on or from the optical disk is actively developed.
When video data recorded on or played back from the DVD-RAM is edited according to the DVD standard, it is necessary to effect the editing operation using the authoring system as in the conventional DVD-ROM. For this reason, there occurs a problem that it takes a long time and much labor for the user and the financial burden for preparing a device for the authoring system is imposed on the user.